Some of the prime minister’s critics suggested this week that Stephen Harper chose the date of Monday’s byelections to give his Tory troops an underhanded edge.

Scheduling the trip to the polls on the day between a weekend and the Canada Day holiday was a trick, the theory goes, aimed at reducing the turnout of traditional non-Conservative voters, who are known for enjoying summer, unlike Conservatives, who care nothing for docks, boats, water wings, wading pools or ice cream cones.

I don’t think so.

It is fair, I think, to judge the prime minister harshly for selecting a byelection date that presented voters with a choice between an extra day at the cottage and their civic duty, but I don’t think he set the date because he was worried about losing the Tory bastions the party held.

I think he held the vote when he did because he had a pretty good idea that the story the byelections tell would not help him, and he didn’t want voters paying attention.

The byelections saw the Liberals increase their vote impressively while the Tories and NDP lost ground, contributing to a growing sense — call it Justinmentum or dauphinmania — that Canadians want Justin Trudeau to lead them.

Liberal leader Justin Trudeau and his children Xavier, left and Ella-Grace walk downtown in Calgary on July 4, 2014. Photo by Leah Hennel/Calgary Herald

Since Trudeau became leader of the third party 15 months ago, he has been steadily ahead of Harper and NDP Leader Tom Mulcair in the polls. In all nine byelections since then, the Liberal vote has grown. In two of them, the Liberals took seats from their rivals.

In several Western seats, the Liberals have posed a real threat for the first time since Justin’s dad brought in the National Energy Program.

Financial reports released this week show the Conservative fundraising advantage is fading. The Liberals raised $11 million last year — up from the $4 million the party raised in 2007 — although still less than the $18 million the Tories raised.

A feeling of inevitability is settling in around the rise of the Trudeau fils, which doesn’t do anything to weaken the constitutional powers vested in Harper, but can’t be doing wonders for his mood, the mood of his caucus or the legion of political staffers who run the country at his direction.

The idea that Harper is a lame duck — a leader with a lot more past than future — is corrosive.

Unlike former prime minister Brian Mulroney, who always had his caucus wrapped around his little finger, Harper has always relied more on the carrot and the stick than reciprocal personal affection.

Prime Minister Stephen Harper horses around with some colourful performers during the Stampede Parade in Calgary on Friday July 4, 2014. (Jenn Pierce/Calgary Herald)

The impressive solidarity of the Conservative caucus, best observed in MPs’ silence and unprecedented and scrupulous adherence to talking points, seems to be a result of Harper’s careful management of the hierarchy, not personal affection for the boss.

This kind of structure — where caucus members fear reprisals and hope for advancement — depends for its continued smooth functioning on the idea that the boss will still be the boss in days ahead.

If that sense is shaken, and MPs become fearful and rattled, they are more likely to go off script, to stop caring so much what the boys in short pants in the Prime Minister’s Office want them to do, to start thinking about what they can do to keep their seats, work on other career plans or try to poodle up to whoever might run the party after Harper.

The fact that there hasn’t been more of this kind of thing already is a tribute to the shared sense of mission, the party’s centralized control over data, messaging and nominations, and the fact that Harper founded the party and led it to power.

The situation is at least as threatening to Mulcair, since voters who would like to see the back of Harper seem to be settling on Trudeau as the alternative.

Federal NDP Leader Thomas Mulcair speaksin this file photo. THE CANADIAN PRESS/Chris Young

Mulcair is still the most popular politician in Quebec, and his party hopes it can make gains in British Columbia, but the hope that it can form government next year seems to be growing slimmer.

It must be depressing for Mulcair and his front benchers to observe that their strong work opposing the Election Act and prosecuting Harper on the Senate scandal hasn’t resonated with voters, but it hasn’t.

Both the Tories and the NDP have the summer to ponder the lessons of the byelections and make new plans. For the NDP, that may mean tacking to the left, taking stronger positions against trade deals and pipelines that Liberals support, trying to drive a wedge between left-leaning voters and the Grits.

And the Tories may want to rethink their attempt to humiliate and impoverish the NDP for rule-breaking mailings and satellite offices, since they need vote splitting.

They also might be wise to attempt a more thoughtful critique of Trudeau, abandoning cartoonish attack ads aimed at his marijuana policy, in favour of more pointed questions about whether this likable young man is really qualified to run a $1.8-trillion economy.